It is well-known in northern climates to use automotive block heaters during the winter months. Such heaters maintain the engine block and oil temperatures well above the ambient temperatures. Similar heaters are available for automotive radiators and batteries.
Unfortunately, since such equipment must be manufactured to stand up under the most extreme weather conditions, it is often the case that excessive power is consumed under standard or milder conditions. This is true not only of automotive block, radiator and battery heaters, but also heaters used in animal husbandry, such as those used to prevent the drinking water of livestock from freezing. As a result, money is wasted in operation during all but the most extreme weather conditions.
As a result, power sharing devices have been developed to cycle power to one or more outlets, thereby lessening the duty cycle of an individual heating apparatus from 100% to some fraction thereof. However, due to their construction, most such power cycling devices lack the functionality required to be fully effective in supplying the amount of power required for the efficient operation of the heating device.
A first flaw common to most power sharing and cycling devices it that the power supply commences at the moment the heating devices are plugged in. As a result, electrical power is expended heating a warm engine.
A second flaw common to many power sharing devices is the use of mechanical construction techniques that result in a high parts count and failure rate, component degradation over time and high cost of manufacture.
An additional flaw common to power sharing devices is that when power is in the off portion of the cycle there is no method and supporting circuit that allows the user to determine if the power is simply in the off portion of the cycle, or if there has been a circuit failure.
A still further flaw common to most power sharing devices is that the user has little or no control over the duty cycle of the power distribution.
For the foregoing reasons, there is a need for power sharing device that can, at the user's option, delay the inception of the operation of the heating device. The power sharing device must be able to function in any ambient temperature, and must be extremely reliable. The power sharing device must provide the user with control over the power duty cycle at which the heating devices are operated. Also, the power sharing device must provide the user with circuitry to test all outlets to determine if power is being supplied and to determine if there is a circuit failure.